The present invention relates to a benzofuran derivative possessing a JAK-STAT 6 phosphorylation inhibitory effect, and to a pharmaceutical composition containing the benzofuran derivative as an active ingredient.
Interleukin 4 is a cytokine involved in the onset and progress of inflammation, specifically known to be a factor leading to exacerbation of atopic dermatitis. Production of interleukin 4 is known to be accelerated by phosphorylation of STAT 6. This phenomenon is confirmed by the fact that interleukin 4 is blocked in STAT 6-knocked-out mice. Specifically, when phosphorylation of START 6 is suppressed by use of an agent, the reaction associated with such an interleukin 4 is inactivated effectively. On the basis of such findings, attention is paid particularly for the mechanism suppressing the inflammation caused by allergy through suppression of JAK-STAT 6, thus there has been strong demand for developing a means capable of inhibiting the phosphorylation of START 6.
Thus, an object of the present invention is to provide an STAT 6 phosphorylation inhibiting compound. Another object of the invention is to provide a pharmaceutical composition containing the compound useful for treating or preventing allergic disorders.
In view of the foregoing, the present inventors have carried out extensive studies in order to provide an STAT 6 phosphorylation inhibiting compound, and have found that benzofuran derivatives represented by the below-mentioned formula (I) and salts thereof exert an STAT 6 phosphorylation inhibitory effect. The present invention has been accomplished on the basis of this finding. Specifically, the present invention is directed to the following technical scopes described hereinbelow.
Accordingly, the present invention provides a benzofuran derivative represented by formula (I) or a salt thereof: 
(wherein R1 represents a phenyl group or a hydrogen atom; k is 0 or 1; each of m, n, o, p, and q is an integer of 0 to 5; and each of R2 and R3 represents a hydrogen atom or a hydroxyl group, or R2 and R3 together represent an oxygen atom, with proviso that k, q, and m, or n, o, and p are not simultaneously 0).
The present invention also provides a pharmaceutical composition and a JAK-STAT 6 phosphorylation inhibitor, the composition and inhibitor containing, as an active ingredient, a benzofuran derivative represented by formula (I) or a salt thereof.
The present invention also provides use of a benzofuran derivative represented by formula (I) or a salt thereof for producing a drug.
The present invention also provides a method for treating an allergic disorder characterized in that the method comprises administering, in an effective amount, a benzofuran derivative represented by formula (I) or a salt thereof.